When the provider is really fast, people feel like they were overcharged.
This would not happen with services that people have more experience with.
Also being faster doesn't always add value to the customer, but it does help the provider, so people are unwilling to pay for it. They figure if he's fast he can do more business per day.
(Obviously this depends on the situation, but if you wait for an hour for the locksmith to arrive, him taking 1 minute or 15 doesn't really matter much to you.)
Except for that putting on a show is the key to success in almost every industry, whether you're an author, entrepreneur, salesperson, financial analyst, doctor, grocery store, etc. In fact the only area I can think of where this isn't the case is in amateur sports, which is telling.
On the other hand, I have very little understanding of how much time/effort is required by doctors and financial analysts, so I could easily be tricked by them.
Maybe not quite as universal as claimed by the OP but he definitely has a point.
I am willing to pay the sticker price for the groceries I pull off the shelf, not the cashier's skill in ringing them up.